Coated medical devices, such as stents, catheters, guide wires, vascular grafts and the like, are frequently used in numerous medical procedures. The utility of these devices may be enhanced by therapeutic, diagnostic, lubricious or other materials coated onto the device which can be delivered, or released, from the device to a specific site within the patient. With the number of medical procedures utilizing medical devices such as stents and catheters, it would be desirable to provide coated medical devices that release therapeutic or diagnostic agents within a patient in a controlled manner.
A conventional technique for introducing a drug into a medical device coating is to apply the coating to the device, swell the coating in a solvent in the presence of a drug that is dissolved in the solvent, and to remove the solvent. The swelling of the coating allows the drug to interpenetrate the coating, where it remains after the solvent is removed.